Aerosol antiperspirant composition

ABSTRACT

A SINGLE LIQUID PHASE AEROSOL ANTIPERSPIRANT COMPOSITION CONTAINING A DISSOLVED INORGANIC ASTRINGENT SALT, AN ALCOHOL, AN EROSOL PROPELLANT, A SODIUM, POTASSIUM OR AMMONIUM SALT OF AN ARYL SULFONIC ACID AND WATER, IN SPECIFIED PROPORTIONS.

United States Patent 3,555,145 AEROSOL ANTIPERSPIRANT COMPOSITION Thomas Andrew Wetzel and James A. Hellyer, Cincinnati, Ohio, assignors to The Procter & Gamble Company, Cincinnati, Ohio, a corporation of Ohio No Drawing. Filed Dec. 23, 1965, Ser. No. 516,117 Int. Cl. A61k 7/00 US. Cl. 424-47 6 Claims ABSTRACT OF THE DISCLOSURE A single liquid phase aerosol antiperspirant composition containing a dissolved inorganic astringent salt, an alcohol, an aerosol propellant, a sodium, potassium or ammonium salt of an aryl sulfonic acid and water, in specified proportions.

This invention relates to a perspiration inhibiting composition containing an astringent inorganic salt as the active ingredient, and more particularly to an aerosol form of said composition.

The wide consumer acceptance of various cosmetic products in aerosol form has led researchers to direct their efforts to the formulation of personal deodorant products in this form. Because of the many problems met in attempting to incorporate the usual antiperspirant materials in aerosol systems, a cosmetically acceptable and effective antiperspirant product in this form has not reached the market place. (A discussion of the problem is presented by F. T. Reed, Aerosol Antiperspirant Studies, Freon Aerosol Report 8A, E. I. du Pont de Nemours, Inc.). Most currently available aerosol products have deodorant properties only and do not possess significant antiperspirant activity. In spite of this shortcoming, consumers desire and use aerosol deodorants.

An aerosol product which possesses the attractive cosmetic properties and convenience benefits of currently available aerosol deodorant products and which additionally provides substantial antiperspirant effects would be highly desirable. Since the inorganic astringent salts possess for greater antiperspirant activity than the organic astringent salts heretofore suggested for aerosol use, the inorganic salts must be used, in spite of the formulation problems which this entails, to provide such a product.

Aerosol antiperspirant compositions based on inorganic astringent salts must contain four primary components: an astringent salt (the active antiperspirant ingredient);

water; alcohol; and an aerosol propellant. Water is necessary as a solvent for the active antiperspirant ingredient in such compositions, common astringent salts being effective only when dissolved in and applied to the body from an aqueous medium. The aqueous solution containing the dissolved astringent salt is substantially insoluble in the aerosol propellant and thus two liquid phases tend to form when these solutions are admixed. A single liquid phase system is highly desirable in such compositions; otherwise, manual shaking of the aerosol container prior to use is necessary in order to insure (1) proper dispensing from the container and (2) uniform application of the composition on the user. Therefore, an alcohol which is miscible with both the aqueous astringent salt solution and the propellant solution is used to maintain a single liquid phase. However, efforts to use alcohol for the purpose of maintaining a single liquid phase system have been successful only in compositions containing low levels of water. In any event, the amount of alcohol which can be used in such compositions is limited by the effect which this component has on the physical characteristics of the aerosol spray during the ultimate use of the end product.

Patented Jan. 12, 1971 The efficacy of an antiperspirant composition is largely dependent upon the relative activity and quantity of the astringent salt employed therein. Thus, efficacy can be improved by increasing the concentration of the astringent salt. However, increasing the quantity of this component correspondingly necessitates the use of an increased quantity of water, and, it becomes progressively more diflicult to maintain a single liquid phase system in aerosol antiperspirant compositions as the quantity of water contained therein increases.

Still another problem inherent in increasing levels of astringent salts to improve aerosol antiperspirant efficacy is valve clogging. After use, a quantity of the liquid composition is retained in the valve assembly and upon drying the astringent salt contained therein precipitates in the orifice or elsewhere in the aerosol valve assembly causing it to clog and become inoperative. Valve clogging tends to increase as higher levels of antiperspirant active are used, especially at higher temperatures.

Accordingly, it is a primary object of this invention to provide improved aerosol antiperspirant compositions.

It is a further object of this invention to provide single liquid phase aerosol antiperspirant compositions which exhibit a high degree of antiperspirant efficacy.

It is a more specific object of this invention to provide single liquid phase aerosol antiperspirant compositions having desirable spray characteristics, relative freedom from valve clogging and which contain highly effective levels of inorganic astringent salts.

It has now been discovered that these and other objects are achieved by an aerosol antiperspirant composition, which comprises certain critical concentrations of an inorganic astringent salt, a low molecular weight alcohol, an aerosol propellant and an alkali metal salt of an aryl sulfonic acid, all as more fully defined hereinafter.

A wide variety of astringent inorganic salts having antiperspirant efficacy are known in the art and can be used in the compositions of this invention. For example, useful astringent salts include zirconium salts such as zirconium chloride, zirconium hydroxychloride and zirconium sulfate; zinc salts such as zinc chloride, zinc sulfate and zinc phosphate; and iron salts such as ferric chloride and ferrous sulphate. Aluminum salts such as aluminum chloride, aluminum sulfate, aluminum oxychloride and hydrates of these aluminum salts, e.g., aluminum chloride hexahydrate AlCl 6H O are especially preferred.

Aluminum chlorhydrate (hereinafter referred to as ACH) represents a highly preferred antiperspirant for use herein. ACH is a known antiperspirant compound; it has been referred to as aluminum chlorhydroxide complex or basic aluminum chloride. In general, ACH has an approximate atomic ratio of aluminum to chlorine of 2:1, e.g., 2.1 to 1.9: 1, and an empircal formula of Al (OH) Cl in aqueous solution.

Mixtures of astringent salts can also be used. For example, zirconyl hydroxy chloride having the empirical formula ZrOOHCl can be used in conjunction with an aluminum chlorhydroxide complex as disclosed by Grad in US. Pat. 2,854,382, granted June 25, 1957.

The astringent salt is present in the compositions of this invention in an amount ranging from about 6% to about 15%, preferably from about 8% to about 12%.

The 6% lower limit is considered to be the minimum level of active necessary for widely acceptable and recognizable antiperspirant efficacy. As the 15% upper limit is approached, it becomes increasingly diflicult to dissolve the active ingredient while simultaneously maintaining a single liquid phase and desirable spray characteristics.

Water must be employed in the aerosol compositions of this invention in an amount ranging from about 6% to about 24%. The minimum quantity of water is determined by the amount required to dissolve the astringent salt. The maximum quantity of water is governed by the necessity of maintaining a single liquid phase. Preferably, the quantity of water ranges from about to about The low molecular weight alcohols which can be used in the composition are those which are miscible in both water and aerosol propellants. Lower aliphatic alcohols such as methanol, ethanol, n-propanol, isopropanol, propylene glycol, ethylene glycol, n-butanol, isobutanol, or the like, represent examples of preferred alcohols. n- Butanol, isopropanol and ethanol are particularly preferred as the alcohol component with ethanol being the most highly preferred.

The alcohol component is present in the compositions of the invention in an amount ranging from about to about 60%, preferably from about to about The 30% lower limit is the minimum quantity of alcohol necessary to maintain a single liquid phase. As the amount of alcohol approaches about the spray characteristics of the product become too wet and coldfeeling for consumer acceptance.

The aerosol propellant can be any suitable liquefied, normally gaseous, organic material. In general, the material should be substantially nontoxic, relatively nonflammable, lowboiling, odorless, and the like. Suitable propellants include liquefied, normally gaseous, low molecular weight hydrocarbon materials such as dimethyl ether, or halogented hydrocarbons such as halogenated methane, ethane, propane, butane, pentane, and mixtures thereof. Other halogenated hydrocarbons materials which have been found to be particularly suitable for use as propellants in accordance with the present invention include dichloromonofiuoromethane (Freon 21), monochlorodifluoroethane (Freon 142b), dichlorodifluoromethane (Freon 12), di-chlorotetrafluoroethane (Freon,

114), monochlorotrifiuoromethane Isotron 133a), difluoroethane (Freon 152a), and the like.

In some instances it may be desirable to use a combination of two or more of the liquefied, normally gaseous, materials as a propellant in order to achieve a suitable pressure within the container, i.e., a pressure in the range of about 5 p.s.i.g. to about 100 p.s.i.g., preferably from 15 p.s.i.g. to about 35 p.s.i.g., at F.

Particularly preferred propellants or mixtures thereof are fluorochlorohydro'carbons such as Freon 142b; a mixture of 25% Freon 152a and Isotron 133a; a mixture of 25% Freon 152a and 75% Freon 21; a mixture of 50% Freon 142i) and 50% lsotron 133a; a mixture of 25% Freon 12 and 75% Freon 21; and a mixture of 25% Freon 12 and 75% Freon 114. Freon 142b (monochlorodifiuoroethane) represents the most preferred propellant.

The aerosol propellant is present in the antiperspirant compositions of this invention in an amount ranging from about 15% to about 45%, preferably from about 20% to about 40%. The minimum quantity of propellant is governed by the need for an adequate pressure to exhaust the contents of the container and to provide a cosmetically acceptable spray; at least 15% propellant is deemed necessary for this purpose.

The characterizing ingredient of the compositions of this invention is the alkali metal salt of an aryl sulfonic acid. Examples of useful compounds are the alkali metal salts of benzene, xylene and toluene sulfonate. Sodium or potassium toluene sulfonate are preferred salts. Surprisingly, the presence of this component in certain critical proportions, enables one to increase the quantity of dissolved astringent salt, increase the quantity of water, and yet maintain a single liquid phase and desirable spray characteristics. Further, this component unexpectedly alleviates the valve clogging problem hereinbefore discussed.

The alkali metal aryl sulfonates must be present in the aerosol antiperspiratn compositions of this invention in certain critical amounts in order to realize the abovediscussed advantages. Specifically, this component is present in the compositions of this invention in an amount ranging from about 0.25 to about 6%. Compositions containing less than about 0.25 and more than about 6% of alkali metal aryl sulfonate exhibit two liquid phases and/or undissolved astringent salt. Preferably the aryl sulfonate component is present in an amount of from about 0.5 to about 4.0%

The aerosol antiperspirant compositions of this invention can also contain, if desired, minor proportions, i.e., up to about 5%, of various auxiliary ingredients such as perfume, coloring agents, emollients, antibacterial agents, e.g., hexachlorophene, and boilers, e.g., urea. Such components are preferred but not essential to the composition.

The pH of the compositions of this invention preferably ranges from about 2.5 to about 6, most preferably from about 3 to about 5.

The compositions herein disclosed can be prepared in any suitable manner. A satisfactory method comprises admixing the astringent salt with water, alcohol and sulfonate salt, and adding this mixture to the aerosol container which is subsequently sealed. Thereafter, the propellant while under air pressure can be admitted to the container through a valve or by other appropriate means. The container is then generally placed in a F. temperature bath for about five minutes to test for leakage and the like. Other similar aerosol-filling techniques are well known and are readily adaptable to packaging the compositions of this invention in appropriate aerosol containers.

The compositions of this invention can be packaged in suitable pressure-tight containers. For pressures lower than about 40 p.s.i.g. at 70 F., glass bottles which are coated on the outside with plastic, and metal cans are suitable. Metal cans are preferably employed for higher pressures. A metal which is not appreciably corroded by the product should be chosen, e.g., stainless steel.

The valves, with which the pressurized containers are fitted to control their opening and discharge of product, are those commonly employed for other aerosol compositions, e.g., aerosol deodorant products.

In conjunction with the valve, it is preferable to use (a) a conventional aerosol dip tube which extends into container in contact with the liquid phase of the product, and (b) a conventional aerosol stem which is connected to a nozzle.

The nozzle (or button) for ultimate discharge of the product from the container is not critical; it is preferred however, to use a mechanical break-up nozzle, i.e., a nozzle that provides a finely dispersed spray.

All percentages and parts herein and in the appended claims are by weight unless otherwise indicated.

The aerosol antiperspirant compositions of Examples I-IX in Table 1 were prepared by a conventional aerosolfilling technique outlined as follows:

Weighed portions (percentages by Weight shown in Table 1) of the astringent salt, Water, alcohol, and alkali metal aryl sulfonate, were admixed in a 4 oz. Boston Round plastic-coated glass bottle aerosol container. A con ventional aerosol bottle valve having a stern and a dip tube was placed on the container. The container was then passed through a vacuum crimper which drew a vacuum in the container and tightly secured the valve. The propellant was then added to the container through and around the stem of the valve under a pressure of about 500 p.s.i.g. The container was then placed in a 140 F. Water bath for 5 minutes to check for leakage. None of the containers prepared in the following examples exhibited leakage.

Transparent containers were used to enable visual examination of the compositions contained therein; thus, it could readily be determined, for example, if the astringent salt had totally dissolved and/or Whether a single liquid phase existed.

TABLE 1 Potassium Aluminum Ethyl toluene Monochlorodi- Example chlorhydrate Water alcohol sulfonate fluoroethane 6. 22. 0 40. O 2. 0 30. 0 7.0 20.0 42.0 1.0 30.0 8. 0 19. 0 42.0 1. 0 30. 0 8.0 20. 0 40. 0 2. 0 30. 0 9. 0 19. O 40. 0 2. 0 30. 0 10. 0 17. 0 41. O 2. 0 30. 0 10. 0 15. 0 43. 0 2. 0 30. 0 l2. 0 14. 0 42. 0 2. 0 30. 0 15. 0 15.0 36. 0 4. 0 30. 0

Each of the compositions in Examples I-IX of Table l was characterized in that the astringent salt was totally dissolved, and a single liquid phase was observed. In addition, each of these compositions exhibits outstanding antiperspirant efficacy, desirable spray characteristics, and a relative freedom from valve clogging. The internal pressure in the containers containing the compositions of Examples IIX ranged from to 35 p.s.i.g. at 70 F.; the pH of these compositions ranged from about 3 to 5. Identical compositions, but not containing an alkali metal aryl sulfonate are prepared and are found to contain undissolved astringent salt and/or exhibit two liquid phases.

The aerosol antiperspirant compositions of Examples XXX listed in Table 2 below are prepared by the aerosolfilling technique outlined for Examples I-IX above. Each composition has the astringent salt totally dissolved and has a single liquid phase. In addition, each composition exhibits a high degree of antiperspirant efiicacy, desirable spray characteristics, and relative freedom from valve clogging. The containers containing these compositions have an internal pressure ranging from about 15 to about 35 p.s.i.g. at 70 F.; these compositions have a pH ranging from about 3 to 5.

sium or ammonium salt of an aryl snlfonic acid selected from the group consisting of benzene sulfonic acid, xylene sulfonic acid and toluene sulfonio acid.

2. The composition of claim 1 wherein the dissolved inorganic astringent salt is selected from the group consisting of aluminum chloride, aluminum oxychloride and aluminum chlorhydrate.

3. The composition of claim 1 wherein the salt of an aryl sufonic acid is selected from the group consisting of sodium toluene sulfonate and potassium toluene sulfonate.

4. A single phase aerosol antiperspirant composition, which comprises:

(A) from about 8% to about 12% of a dissolved inorganic astringent aluminum salt selected from a group consisting of aluminum chloride, aluminum sulfate, aluminum oxychloride and aluminum, chlorhydrate (B) from about 10% to about 20% water (C) from about 35% to about 55% of a low molecular weight aliphatic alcohol selected from a group consisting of methanol, ethanol, n-propanol, isopropanol, propylene glycol, ethylene glycol, nbntanol and isobutanol (D) from about 25% to about of a liquefied normally gaseous aerosol propellant, selected from the group consisting of dichloromonofluoromethane, monochlorodifluoroethane, dichlorodifluormethane, dichlorotetrafluoroethane, monochlorotrifiuoromethane, difluoroethane, and mixtures thereof; and

(E) from about 0.5% to about 4% of a sodium or potassium salt of an aryl sulfonic acid selected from the group consisting of benzene sulfonic acid, xylene sulfonic acid and toluene sulfonic acid.

TABLE 2 Water, Example Astringent salt, percent percent Alcohol, percent Alkali metal aryl sulfonate, percent Propellant, percent X Zinc sulfate, 10 22 Isopropanol, 35 Sodium benzene sulfonate, 2 Dimethyl ether, 21. XI Zinc chloride, 7 14 Methanol, 33.751- Potassium benzene sulfonate, 0.25. Dichloromonofiuoromethane, 45. XII Zinc phosphate, 8.-. 16 Ethanol, 60 Sodium xylene sulfonate, 0.5 Dichlorodifiuoromethane, 15.5. XIII Ferric chloride, 9-"- 18 n-Propanol, 32 Potassium xylene sulfonate, 1 Dichlorotetrafluoroethane. XIV Ferrous sulphate, 10 20 Isopropanol, 30 Sodium benzene sulfonate, 2 Monochlorotrifluoroethane, 38. XV. Zirconium hydroxychloride, 11.- 22 Butanol, 30 Potassium benzene sulfonate, 3 Difinoroethane, 36. XVI" Zirconium sulfate, 12 24 Propylene glycol, 30 Ammonium benzene sulfonate, 4. 25% difiuoroethane; 75% monochlorotritluoroethane, 30. XVII Aluminum chloride, 13 24 Ethylene glycol, 33 Potassium xylene sulfonate, 5 25% difiuoroethane; 75% diehloromonofiuoromethane. 25. XVIIL... Aluminum sulfate, 14 24 Isopropanol, 36.5 Ammonium toluene sulfonate, 5.5 Monochloroethane, 20. XIX Aluminum oxychloride, l5 24 n-Propanol, 40 Sodium toluene sulfonate, 6 Dichloropentane, 15. XX Aluminum chlorhydrate, 9 18 Ethanol, 41 Potassium toluene sulfonate, 2 Monochlorodifiuoroethane, 30.

We claim: 5. The composition of clann 4 wherein the low mo- 1. A single liquid phase aerosol antiperspirant composition, which comprises:

(A) from about 6% to about 15% of a dissolved inorganic astringent metallic salt selected from the group consisting of zirconium chloride, zirconium hydroxychloride, zirconium sulfate, zinc chloride, zinc sulfate, zinc phosphate, ferric chloride, ferrous sulfate, aluminum chlorohydrate, aluminum chloride, aluminum sulfate, aluminum oxychloride, aluminum chloride hexahydrate and mixtures thereof;

(B) from about 6% to about 24% water;

(C) from about 30% to about of a low molecular weight alcohol, selected from the group consisting of methanol, ethanol, n-propanol, isopropanol, propylene glycol, ethylene glycol, nl-butanol and isobutanol;

(D) from about 15% to about 45% of a liquefied normaly gaseous aerosol propellant selected from the group consisting of dimethyl ether, dichloromonofluoromethane, monochlorodifluoroethane, dichlorodifluoromethane, dichlorotetrafluoroethane, monochlorotrifluoromethane, difluoroethane, and mixtures thereof; and

(E) from about .25 to about 6% of a sodium, potas- References Cited UNITED STATES PATENTS 3,088,874 5/1963 Geary et al. 16782 3,141,821 7/1964 Compeau 16758 FOREIGN PATENTS 987,301 3/ 1965 Great Britain 167--90 OTHER REFERENCES Schwartz 'et al.: 1958, vol. II, Surface Active Agents and Detergents, pp. 286, 487, 488, 607, and 608.

ALBERT T. MEYERS, Primary Examiner D. R. OVRE, Assistant Examiner US. Cl. X.R. 424-65, 66, 67, 68 

